Contact device for resistors



July 18, 1933 A. H. HARDwlcK CONTACT DEVICE FOR RESlSTORS Filed July 24, 1930 da Mn N Mmm my am W om m Patented July 18, 1933 UNITED STATES PATENT OFFICE AMBROSE H. HARDWICK, F EAST ORANGE, NEW JERSEY, ASSIGNOR TO HARDWICK, HINDLE, INC., OF NEWARK, NEW JERSEY, A CORPORATION 0F NEW JERSEY CONTACT DEVICE FOR RESISTORS application. aled :any 24,

This invention relates to contact devices for resistors and while of general utility is particularly adapted for use with resistors of the type shown in the copending applications oi' George B. Crouse, Serial Nos. 470,380, and 470,381, and filed July 24, 1930, for resistors.

In these applications there are shown resistors of the vitreous enamel type provided with areas throughout which the wire is exposed in order that electrical contact may be made therewith Aat any desired point.

It is an object of this invention to provide a contact device which may be adjustably set with respect. to the resistor at a point to include the desired resistance between the device and a terminal of the resistor and thereafter the device may be permanently connected to the resistor at this same point, thus avoiding any difference between the resistance for which the device is initially positioned and the final resistance of the resistor.

T he particular nature of the invention as well as other objects and advantages thereof will appear most clearly froma description of a preferred embodiment thereof as shown in the accompanying drawing in which:

Fig. 1 is a View of a resistor with the contact device in place thereon, and

Fig. 2 is an enlarged transverse sectional View along the line 2-2 of Fig. 1.

In Fig. 1, 1 indicates generally a resistor consisting of a refractory tube 2 on ,which is wound a wire 3 having its ends attached to contact bands 4, having outwardly extending ends 5 which serve as terminals and to one of which a binding post 6 is attached. The wire 3 is exposed throughout a longitudinal track 7, this feature of the resistor being in accordance with the inventions of the copending applications referred to above.

The contact device consists of a band 8 surrounding the resistor and having outwardly extending ends 9. The band may be 'clamped upon the .resistor at any desired point by means of a screw 10 and a nut 1:1. The screw is also provided with washers 12 and a binding nut 13 for connection to an external circuit.

The band is formed with a depression 14 50 which engages the exposed wire of the re- 1930. Serial No. 470,422.

sistor at the desired point of adjustment, the arrangement being such that the depression engages only a few of the turns of the wire. The depression is provided with a hole 15 so that after the device has been properly set it may be permanently xed to the wire, by placing in the depression a drop of solder and the necessary linx. The solder is melted by a thin blow-torch flame and runs through the hole thereby connecting the device to the wire at the exact point of adjustment.

`While for illustration the contact device has been shown applied to a particular form of resistor, it will be understood that it may be applied to other types of resistors and that various changes may be made in its details of construction without departing from the principle of the invention as defined in the appended claims.

I claim:

1. A contact device for a resistor consisting of a band surrounding the resistor and means for clamping the band in place on the resistor, said band being provided with a depression engaging the wire of the resistor at a desired point, said depression being provided with an aperture whereby solder placed in the depression may flow into contact with the wire at the said point of engagement.

2. A contact device for a. resistor consisting of a band surrounding the resistor and means for clamping the band in place on the resistor, said band being provided with an inwardly extending portion adapted to engage the wire of the resistor at a desired point, being formed to receive solder and provided with an aperture through which the solder may iow into contact with the wire at the said point of engagen'ient.

AMBROSE H. HARDWICK. 

